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-rw-r--r--net/rds/recv.c832
1 files changed, 832 insertions, 0 deletions
diff --git a/net/rds/recv.c b/net/rds/recv.c
new file mode 100644
index 0000000000..c71b923764
--- /dev/null
+++ b/net/rds/recv.c
@@ -0,0 +1,832 @@
+/*
+ * Copyright (c) 2006, 2019 Oracle and/or its affiliates. All rights reserved.
+ *
+ * This software is available to you under a choice of one of two
+ * licenses. You may choose to be licensed under the terms of the GNU
+ * General Public License (GPL) Version 2, available from the file
+ * COPYING in the main directory of this source tree, or the
+ * OpenIB.org BSD license below:
+ *
+ * Redistribution and use in source and binary forms, with or
+ * without modification, are permitted provided that the following
+ * conditions are met:
+ *
+ * - Redistributions of source code must retain the above
+ * copyright notice, this list of conditions and the following
+ * disclaimer.
+ *
+ * - Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following
+ * disclaimer in the documentation and/or other materials
+ * provided with the distribution.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ *
+ */
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <net/sock.h>
+#include <linux/in.h>
+#include <linux/export.h>
+#include <linux/sched/clock.h>
+#include <linux/time.h>
+#include <linux/rds.h>
+
+#include "rds.h"
+
+void rds_inc_init(struct rds_incoming *inc, struct rds_connection *conn,
+ struct in6_addr *saddr)
+{
+ refcount_set(&inc->i_refcount, 1);
+ INIT_LIST_HEAD(&inc->i_item);
+ inc->i_conn = conn;
+ inc->i_saddr = *saddr;
+ inc->i_usercopy.rdma_cookie = 0;
+ inc->i_usercopy.rx_tstamp = ktime_set(0, 0);
+
+ memset(inc->i_rx_lat_trace, 0, sizeof(inc->i_rx_lat_trace));
+}
+EXPORT_SYMBOL_GPL(rds_inc_init);
+
+void rds_inc_path_init(struct rds_incoming *inc, struct rds_conn_path *cp,
+ struct in6_addr *saddr)
+{
+ refcount_set(&inc->i_refcount, 1);
+ INIT_LIST_HEAD(&inc->i_item);
+ inc->i_conn = cp->cp_conn;
+ inc->i_conn_path = cp;
+ inc->i_saddr = *saddr;
+ inc->i_usercopy.rdma_cookie = 0;
+ inc->i_usercopy.rx_tstamp = ktime_set(0, 0);
+}
+EXPORT_SYMBOL_GPL(rds_inc_path_init);
+
+static void rds_inc_addref(struct rds_incoming *inc)
+{
+ rdsdebug("addref inc %p ref %d\n", inc, refcount_read(&inc->i_refcount));
+ refcount_inc(&inc->i_refcount);
+}
+
+void rds_inc_put(struct rds_incoming *inc)
+{
+ rdsdebug("put inc %p ref %d\n", inc, refcount_read(&inc->i_refcount));
+ if (refcount_dec_and_test(&inc->i_refcount)) {
+ BUG_ON(!list_empty(&inc->i_item));
+
+ inc->i_conn->c_trans->inc_free(inc);
+ }
+}
+EXPORT_SYMBOL_GPL(rds_inc_put);
+
+static void rds_recv_rcvbuf_delta(struct rds_sock *rs, struct sock *sk,
+ struct rds_cong_map *map,
+ int delta, __be16 port)
+{
+ int now_congested;
+
+ if (delta == 0)
+ return;
+
+ rs->rs_rcv_bytes += delta;
+ if (delta > 0)
+ rds_stats_add(s_recv_bytes_added_to_socket, delta);
+ else
+ rds_stats_add(s_recv_bytes_removed_from_socket, -delta);
+
+ /* loop transport doesn't send/recv congestion updates */
+ if (rs->rs_transport->t_type == RDS_TRANS_LOOP)
+ return;
+
+ now_congested = rs->rs_rcv_bytes > rds_sk_rcvbuf(rs);
+
+ rdsdebug("rs %p (%pI6c:%u) recv bytes %d buf %d "
+ "now_cong %d delta %d\n",
+ rs, &rs->rs_bound_addr,
+ ntohs(rs->rs_bound_port), rs->rs_rcv_bytes,
+ rds_sk_rcvbuf(rs), now_congested, delta);
+
+ /* wasn't -> am congested */
+ if (!rs->rs_congested && now_congested) {
+ rs->rs_congested = 1;
+ rds_cong_set_bit(map, port);
+ rds_cong_queue_updates(map);
+ }
+ /* was -> aren't congested */
+ /* Require more free space before reporting uncongested to prevent
+ bouncing cong/uncong state too often */
+ else if (rs->rs_congested && (rs->rs_rcv_bytes < (rds_sk_rcvbuf(rs)/2))) {
+ rs->rs_congested = 0;
+ rds_cong_clear_bit(map, port);
+ rds_cong_queue_updates(map);
+ }
+
+ /* do nothing if no change in cong state */
+}
+
+static void rds_conn_peer_gen_update(struct rds_connection *conn,
+ u32 peer_gen_num)
+{
+ int i;
+ struct rds_message *rm, *tmp;
+ unsigned long flags;
+
+ WARN_ON(conn->c_trans->t_type != RDS_TRANS_TCP);
+ if (peer_gen_num != 0) {
+ if (conn->c_peer_gen_num != 0 &&
+ peer_gen_num != conn->c_peer_gen_num) {
+ for (i = 0; i < RDS_MPATH_WORKERS; i++) {
+ struct rds_conn_path *cp;
+
+ cp = &conn->c_path[i];
+ spin_lock_irqsave(&cp->cp_lock, flags);
+ cp->cp_next_tx_seq = 1;
+ cp->cp_next_rx_seq = 0;
+ list_for_each_entry_safe(rm, tmp,
+ &cp->cp_retrans,
+ m_conn_item) {
+ set_bit(RDS_MSG_FLUSH, &rm->m_flags);
+ }
+ spin_unlock_irqrestore(&cp->cp_lock, flags);
+ }
+ }
+ conn->c_peer_gen_num = peer_gen_num;
+ }
+}
+
+/*
+ * Process all extension headers that come with this message.
+ */
+static void rds_recv_incoming_exthdrs(struct rds_incoming *inc, struct rds_sock *rs)
+{
+ struct rds_header *hdr = &inc->i_hdr;
+ unsigned int pos = 0, type, len;
+ union {
+ struct rds_ext_header_version version;
+ struct rds_ext_header_rdma rdma;
+ struct rds_ext_header_rdma_dest rdma_dest;
+ } buffer;
+
+ while (1) {
+ len = sizeof(buffer);
+ type = rds_message_next_extension(hdr, &pos, &buffer, &len);
+ if (type == RDS_EXTHDR_NONE)
+ break;
+ /* Process extension header here */
+ switch (type) {
+ case RDS_EXTHDR_RDMA:
+ rds_rdma_unuse(rs, be32_to_cpu(buffer.rdma.h_rdma_rkey), 0);
+ break;
+
+ case RDS_EXTHDR_RDMA_DEST:
+ /* We ignore the size for now. We could stash it
+ * somewhere and use it for error checking. */
+ inc->i_usercopy.rdma_cookie = rds_rdma_make_cookie(
+ be32_to_cpu(buffer.rdma_dest.h_rdma_rkey),
+ be32_to_cpu(buffer.rdma_dest.h_rdma_offset));
+
+ break;
+ }
+ }
+}
+
+static void rds_recv_hs_exthdrs(struct rds_header *hdr,
+ struct rds_connection *conn)
+{
+ unsigned int pos = 0, type, len;
+ union {
+ struct rds_ext_header_version version;
+ u16 rds_npaths;
+ u32 rds_gen_num;
+ } buffer;
+ u32 new_peer_gen_num = 0;
+
+ while (1) {
+ len = sizeof(buffer);
+ type = rds_message_next_extension(hdr, &pos, &buffer, &len);
+ if (type == RDS_EXTHDR_NONE)
+ break;
+ /* Process extension header here */
+ switch (type) {
+ case RDS_EXTHDR_NPATHS:
+ conn->c_npaths = min_t(int, RDS_MPATH_WORKERS,
+ be16_to_cpu(buffer.rds_npaths));
+ break;
+ case RDS_EXTHDR_GEN_NUM:
+ new_peer_gen_num = be32_to_cpu(buffer.rds_gen_num);
+ break;
+ default:
+ pr_warn_ratelimited("ignoring unknown exthdr type "
+ "0x%x\n", type);
+ }
+ }
+ /* if RDS_EXTHDR_NPATHS was not found, default to a single-path */
+ conn->c_npaths = max_t(int, conn->c_npaths, 1);
+ conn->c_ping_triggered = 0;
+ rds_conn_peer_gen_update(conn, new_peer_gen_num);
+}
+
+/* rds_start_mprds() will synchronously start multiple paths when appropriate.
+ * The scheme is based on the following rules:
+ *
+ * 1. rds_sendmsg on first connect attempt sends the probe ping, with the
+ * sender's npaths (s_npaths)
+ * 2. rcvr of probe-ping knows the mprds_paths = min(s_npaths, r_npaths). It
+ * sends back a probe-pong with r_npaths. After that, if rcvr is the
+ * smaller ip addr, it starts rds_conn_path_connect_if_down on all
+ * mprds_paths.
+ * 3. sender gets woken up, and can move to rds_conn_path_connect_if_down.
+ * If it is the smaller ipaddr, rds_conn_path_connect_if_down can be
+ * called after reception of the probe-pong on all mprds_paths.
+ * Otherwise (sender of probe-ping is not the smaller ip addr): just call
+ * rds_conn_path_connect_if_down on the hashed path. (see rule 4)
+ * 4. rds_connect_worker must only trigger a connection if laddr < faddr.
+ * 5. sender may end up queuing the packet on the cp. will get sent out later.
+ * when connection is completed.
+ */
+static void rds_start_mprds(struct rds_connection *conn)
+{
+ int i;
+ struct rds_conn_path *cp;
+
+ if (conn->c_npaths > 1 &&
+ rds_addr_cmp(&conn->c_laddr, &conn->c_faddr) < 0) {
+ for (i = 0; i < conn->c_npaths; i++) {
+ cp = &conn->c_path[i];
+ rds_conn_path_connect_if_down(cp);
+ }
+ }
+}
+
+/*
+ * The transport must make sure that this is serialized against other
+ * rx and conn reset on this specific conn.
+ *
+ * We currently assert that only one fragmented message will be sent
+ * down a connection at a time. This lets us reassemble in the conn
+ * instead of per-flow which means that we don't have to go digging through
+ * flows to tear down partial reassembly progress on conn failure and
+ * we save flow lookup and locking for each frag arrival. It does mean
+ * that small messages will wait behind large ones. Fragmenting at all
+ * is only to reduce the memory consumption of pre-posted buffers.
+ *
+ * The caller passes in saddr and daddr instead of us getting it from the
+ * conn. This lets loopback, who only has one conn for both directions,
+ * tell us which roles the addrs in the conn are playing for this message.
+ */
+void rds_recv_incoming(struct rds_connection *conn, struct in6_addr *saddr,
+ struct in6_addr *daddr,
+ struct rds_incoming *inc, gfp_t gfp)
+{
+ struct rds_sock *rs = NULL;
+ struct sock *sk;
+ unsigned long flags;
+ struct rds_conn_path *cp;
+
+ inc->i_conn = conn;
+ inc->i_rx_jiffies = jiffies;
+ if (conn->c_trans->t_mp_capable)
+ cp = inc->i_conn_path;
+ else
+ cp = &conn->c_path[0];
+
+ rdsdebug("conn %p next %llu inc %p seq %llu len %u sport %u dport %u "
+ "flags 0x%x rx_jiffies %lu\n", conn,
+ (unsigned long long)cp->cp_next_rx_seq,
+ inc,
+ (unsigned long long)be64_to_cpu(inc->i_hdr.h_sequence),
+ be32_to_cpu(inc->i_hdr.h_len),
+ be16_to_cpu(inc->i_hdr.h_sport),
+ be16_to_cpu(inc->i_hdr.h_dport),
+ inc->i_hdr.h_flags,
+ inc->i_rx_jiffies);
+
+ /*
+ * Sequence numbers should only increase. Messages get their
+ * sequence number as they're queued in a sending conn. They
+ * can be dropped, though, if the sending socket is closed before
+ * they hit the wire. So sequence numbers can skip forward
+ * under normal operation. They can also drop back in the conn
+ * failover case as previously sent messages are resent down the
+ * new instance of a conn. We drop those, otherwise we have
+ * to assume that the next valid seq does not come after a
+ * hole in the fragment stream.
+ *
+ * The headers don't give us a way to realize if fragments of
+ * a message have been dropped. We assume that frags that arrive
+ * to a flow are part of the current message on the flow that is
+ * being reassembled. This means that senders can't drop messages
+ * from the sending conn until all their frags are sent.
+ *
+ * XXX we could spend more on the wire to get more robust failure
+ * detection, arguably worth it to avoid data corruption.
+ */
+ if (be64_to_cpu(inc->i_hdr.h_sequence) < cp->cp_next_rx_seq &&
+ (inc->i_hdr.h_flags & RDS_FLAG_RETRANSMITTED)) {
+ rds_stats_inc(s_recv_drop_old_seq);
+ goto out;
+ }
+ cp->cp_next_rx_seq = be64_to_cpu(inc->i_hdr.h_sequence) + 1;
+
+ if (rds_sysctl_ping_enable && inc->i_hdr.h_dport == 0) {
+ if (inc->i_hdr.h_sport == 0) {
+ rdsdebug("ignore ping with 0 sport from %pI6c\n",
+ saddr);
+ goto out;
+ }
+ rds_stats_inc(s_recv_ping);
+ rds_send_pong(cp, inc->i_hdr.h_sport);
+ /* if this is a handshake ping, start multipath if necessary */
+ if (RDS_HS_PROBE(be16_to_cpu(inc->i_hdr.h_sport),
+ be16_to_cpu(inc->i_hdr.h_dport))) {
+ rds_recv_hs_exthdrs(&inc->i_hdr, cp->cp_conn);
+ rds_start_mprds(cp->cp_conn);
+ }
+ goto out;
+ }
+
+ if (be16_to_cpu(inc->i_hdr.h_dport) == RDS_FLAG_PROBE_PORT &&
+ inc->i_hdr.h_sport == 0) {
+ rds_recv_hs_exthdrs(&inc->i_hdr, cp->cp_conn);
+ /* if this is a handshake pong, start multipath if necessary */
+ rds_start_mprds(cp->cp_conn);
+ wake_up(&cp->cp_conn->c_hs_waitq);
+ goto out;
+ }
+
+ rs = rds_find_bound(daddr, inc->i_hdr.h_dport, conn->c_bound_if);
+ if (!rs) {
+ rds_stats_inc(s_recv_drop_no_sock);
+ goto out;
+ }
+
+ /* Process extension headers */
+ rds_recv_incoming_exthdrs(inc, rs);
+
+ /* We can be racing with rds_release() which marks the socket dead. */
+ sk = rds_rs_to_sk(rs);
+
+ /* serialize with rds_release -> sock_orphan */
+ write_lock_irqsave(&rs->rs_recv_lock, flags);
+ if (!sock_flag(sk, SOCK_DEAD)) {
+ rdsdebug("adding inc %p to rs %p's recv queue\n", inc, rs);
+ rds_stats_inc(s_recv_queued);
+ rds_recv_rcvbuf_delta(rs, sk, inc->i_conn->c_lcong,
+ be32_to_cpu(inc->i_hdr.h_len),
+ inc->i_hdr.h_dport);
+ if (sock_flag(sk, SOCK_RCVTSTAMP))
+ inc->i_usercopy.rx_tstamp = ktime_get_real();
+ rds_inc_addref(inc);
+ inc->i_rx_lat_trace[RDS_MSG_RX_END] = local_clock();
+ list_add_tail(&inc->i_item, &rs->rs_recv_queue);
+ __rds_wake_sk_sleep(sk);
+ } else {
+ rds_stats_inc(s_recv_drop_dead_sock);
+ }
+ write_unlock_irqrestore(&rs->rs_recv_lock, flags);
+
+out:
+ if (rs)
+ rds_sock_put(rs);
+}
+EXPORT_SYMBOL_GPL(rds_recv_incoming);
+
+/*
+ * be very careful here. This is being called as the condition in
+ * wait_event_*() needs to cope with being called many times.
+ */
+static int rds_next_incoming(struct rds_sock *rs, struct rds_incoming **inc)
+{
+ unsigned long flags;
+
+ if (!*inc) {
+ read_lock_irqsave(&rs->rs_recv_lock, flags);
+ if (!list_empty(&rs->rs_recv_queue)) {
+ *inc = list_entry(rs->rs_recv_queue.next,
+ struct rds_incoming,
+ i_item);
+ rds_inc_addref(*inc);
+ }
+ read_unlock_irqrestore(&rs->rs_recv_lock, flags);
+ }
+
+ return *inc != NULL;
+}
+
+static int rds_still_queued(struct rds_sock *rs, struct rds_incoming *inc,
+ int drop)
+{
+ struct sock *sk = rds_rs_to_sk(rs);
+ int ret = 0;
+ unsigned long flags;
+
+ write_lock_irqsave(&rs->rs_recv_lock, flags);
+ if (!list_empty(&inc->i_item)) {
+ ret = 1;
+ if (drop) {
+ /* XXX make sure this i_conn is reliable */
+ rds_recv_rcvbuf_delta(rs, sk, inc->i_conn->c_lcong,
+ -be32_to_cpu(inc->i_hdr.h_len),
+ inc->i_hdr.h_dport);
+ list_del_init(&inc->i_item);
+ rds_inc_put(inc);
+ }
+ }
+ write_unlock_irqrestore(&rs->rs_recv_lock, flags);
+
+ rdsdebug("inc %p rs %p still %d dropped %d\n", inc, rs, ret, drop);
+ return ret;
+}
+
+/*
+ * Pull errors off the error queue.
+ * If msghdr is NULL, we will just purge the error queue.
+ */
+int rds_notify_queue_get(struct rds_sock *rs, struct msghdr *msghdr)
+{
+ struct rds_notifier *notifier;
+ struct rds_rdma_notify cmsg;
+ unsigned int count = 0, max_messages = ~0U;
+ unsigned long flags;
+ LIST_HEAD(copy);
+ int err = 0;
+
+ memset(&cmsg, 0, sizeof(cmsg)); /* fill holes with zero */
+
+ /* put_cmsg copies to user space and thus may sleep. We can't do this
+ * with rs_lock held, so first grab as many notifications as we can stuff
+ * in the user provided cmsg buffer. We don't try to copy more, to avoid
+ * losing notifications - except when the buffer is so small that it wouldn't
+ * even hold a single notification. Then we give him as much of this single
+ * msg as we can squeeze in, and set MSG_CTRUNC.
+ */
+ if (msghdr) {
+ max_messages = msghdr->msg_controllen / CMSG_SPACE(sizeof(cmsg));
+ if (!max_messages)
+ max_messages = 1;
+ }
+
+ spin_lock_irqsave(&rs->rs_lock, flags);
+ while (!list_empty(&rs->rs_notify_queue) && count < max_messages) {
+ notifier = list_entry(rs->rs_notify_queue.next,
+ struct rds_notifier, n_list);
+ list_move(&notifier->n_list, &copy);
+ count++;
+ }
+ spin_unlock_irqrestore(&rs->rs_lock, flags);
+
+ if (!count)
+ return 0;
+
+ while (!list_empty(&copy)) {
+ notifier = list_entry(copy.next, struct rds_notifier, n_list);
+
+ if (msghdr) {
+ cmsg.user_token = notifier->n_user_token;
+ cmsg.status = notifier->n_status;
+
+ err = put_cmsg(msghdr, SOL_RDS, RDS_CMSG_RDMA_STATUS,
+ sizeof(cmsg), &cmsg);
+ if (err)
+ break;
+ }
+
+ list_del_init(&notifier->n_list);
+ kfree(notifier);
+ }
+
+ /* If we bailed out because of an error in put_cmsg,
+ * we may be left with one or more notifications that we
+ * didn't process. Return them to the head of the list. */
+ if (!list_empty(&copy)) {
+ spin_lock_irqsave(&rs->rs_lock, flags);
+ list_splice(&copy, &rs->rs_notify_queue);
+ spin_unlock_irqrestore(&rs->rs_lock, flags);
+ }
+
+ return err;
+}
+
+/*
+ * Queue a congestion notification
+ */
+static int rds_notify_cong(struct rds_sock *rs, struct msghdr *msghdr)
+{
+ uint64_t notify = rs->rs_cong_notify;
+ unsigned long flags;
+ int err;
+
+ err = put_cmsg(msghdr, SOL_RDS, RDS_CMSG_CONG_UPDATE,
+ sizeof(notify), &notify);
+ if (err)
+ return err;
+
+ spin_lock_irqsave(&rs->rs_lock, flags);
+ rs->rs_cong_notify &= ~notify;
+ spin_unlock_irqrestore(&rs->rs_lock, flags);
+
+ return 0;
+}
+
+/*
+ * Receive any control messages.
+ */
+static int rds_cmsg_recv(struct rds_incoming *inc, struct msghdr *msg,
+ struct rds_sock *rs)
+{
+ int ret = 0;
+
+ if (inc->i_usercopy.rdma_cookie) {
+ ret = put_cmsg(msg, SOL_RDS, RDS_CMSG_RDMA_DEST,
+ sizeof(inc->i_usercopy.rdma_cookie),
+ &inc->i_usercopy.rdma_cookie);
+ if (ret)
+ goto out;
+ }
+
+ if ((inc->i_usercopy.rx_tstamp != 0) &&
+ sock_flag(rds_rs_to_sk(rs), SOCK_RCVTSTAMP)) {
+ struct __kernel_old_timeval tv =
+ ns_to_kernel_old_timeval(inc->i_usercopy.rx_tstamp);
+
+ if (!sock_flag(rds_rs_to_sk(rs), SOCK_TSTAMP_NEW)) {
+ ret = put_cmsg(msg, SOL_SOCKET, SO_TIMESTAMP_OLD,
+ sizeof(tv), &tv);
+ } else {
+ struct __kernel_sock_timeval sk_tv;
+
+ sk_tv.tv_sec = tv.tv_sec;
+ sk_tv.tv_usec = tv.tv_usec;
+
+ ret = put_cmsg(msg, SOL_SOCKET, SO_TIMESTAMP_NEW,
+ sizeof(sk_tv), &sk_tv);
+ }
+
+ if (ret)
+ goto out;
+ }
+
+ if (rs->rs_rx_traces) {
+ struct rds_cmsg_rx_trace t;
+ int i, j;
+
+ memset(&t, 0, sizeof(t));
+ inc->i_rx_lat_trace[RDS_MSG_RX_CMSG] = local_clock();
+ t.rx_traces = rs->rs_rx_traces;
+ for (i = 0; i < rs->rs_rx_traces; i++) {
+ j = rs->rs_rx_trace[i];
+ t.rx_trace_pos[i] = j;
+ t.rx_trace[i] = inc->i_rx_lat_trace[j + 1] -
+ inc->i_rx_lat_trace[j];
+ }
+
+ ret = put_cmsg(msg, SOL_RDS, RDS_CMSG_RXPATH_LATENCY,
+ sizeof(t), &t);
+ if (ret)
+ goto out;
+ }
+
+out:
+ return ret;
+}
+
+static bool rds_recvmsg_zcookie(struct rds_sock *rs, struct msghdr *msg)
+{
+ struct rds_msg_zcopy_queue *q = &rs->rs_zcookie_queue;
+ struct rds_msg_zcopy_info *info = NULL;
+ struct rds_zcopy_cookies *done;
+ unsigned long flags;
+
+ if (!msg->msg_control)
+ return false;
+
+ if (!sock_flag(rds_rs_to_sk(rs), SOCK_ZEROCOPY) ||
+ msg->msg_controllen < CMSG_SPACE(sizeof(*done)))
+ return false;
+
+ spin_lock_irqsave(&q->lock, flags);
+ if (!list_empty(&q->zcookie_head)) {
+ info = list_entry(q->zcookie_head.next,
+ struct rds_msg_zcopy_info, rs_zcookie_next);
+ list_del(&info->rs_zcookie_next);
+ }
+ spin_unlock_irqrestore(&q->lock, flags);
+ if (!info)
+ return false;
+ done = &info->zcookies;
+ if (put_cmsg(msg, SOL_RDS, RDS_CMSG_ZCOPY_COMPLETION, sizeof(*done),
+ done)) {
+ spin_lock_irqsave(&q->lock, flags);
+ list_add(&info->rs_zcookie_next, &q->zcookie_head);
+ spin_unlock_irqrestore(&q->lock, flags);
+ return false;
+ }
+ kfree(info);
+ return true;
+}
+
+int rds_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
+ int msg_flags)
+{
+ struct sock *sk = sock->sk;
+ struct rds_sock *rs = rds_sk_to_rs(sk);
+ long timeo;
+ int ret = 0, nonblock = msg_flags & MSG_DONTWAIT;
+ DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, msg->msg_name);
+ DECLARE_SOCKADDR(struct sockaddr_in *, sin, msg->msg_name);
+ struct rds_incoming *inc = NULL;
+
+ /* udp_recvmsg()->sock_recvtimeo() gets away without locking too.. */
+ timeo = sock_rcvtimeo(sk, nonblock);
+
+ rdsdebug("size %zu flags 0x%x timeo %ld\n", size, msg_flags, timeo);
+
+ if (msg_flags & MSG_OOB)
+ goto out;
+ if (msg_flags & MSG_ERRQUEUE)
+ return sock_recv_errqueue(sk, msg, size, SOL_IP, IP_RECVERR);
+
+ while (1) {
+ /* If there are pending notifications, do those - and nothing else */
+ if (!list_empty(&rs->rs_notify_queue)) {
+ ret = rds_notify_queue_get(rs, msg);
+ break;
+ }
+
+ if (rs->rs_cong_notify) {
+ ret = rds_notify_cong(rs, msg);
+ break;
+ }
+
+ if (!rds_next_incoming(rs, &inc)) {
+ if (nonblock) {
+ bool reaped = rds_recvmsg_zcookie(rs, msg);
+
+ ret = reaped ? 0 : -EAGAIN;
+ break;
+ }
+
+ timeo = wait_event_interruptible_timeout(*sk_sleep(sk),
+ (!list_empty(&rs->rs_notify_queue) ||
+ rs->rs_cong_notify ||
+ rds_next_incoming(rs, &inc)), timeo);
+ rdsdebug("recvmsg woke inc %p timeo %ld\n", inc,
+ timeo);
+ if (timeo > 0 || timeo == MAX_SCHEDULE_TIMEOUT)
+ continue;
+
+ ret = timeo;
+ if (ret == 0)
+ ret = -ETIMEDOUT;
+ break;
+ }
+
+ rdsdebug("copying inc %p from %pI6c:%u to user\n", inc,
+ &inc->i_conn->c_faddr,
+ ntohs(inc->i_hdr.h_sport));
+ ret = inc->i_conn->c_trans->inc_copy_to_user(inc, &msg->msg_iter);
+ if (ret < 0)
+ break;
+
+ /*
+ * if the message we just copied isn't at the head of the
+ * recv queue then someone else raced us to return it, try
+ * to get the next message.
+ */
+ if (!rds_still_queued(rs, inc, !(msg_flags & MSG_PEEK))) {
+ rds_inc_put(inc);
+ inc = NULL;
+ rds_stats_inc(s_recv_deliver_raced);
+ iov_iter_revert(&msg->msg_iter, ret);
+ continue;
+ }
+
+ if (ret < be32_to_cpu(inc->i_hdr.h_len)) {
+ if (msg_flags & MSG_TRUNC)
+ ret = be32_to_cpu(inc->i_hdr.h_len);
+ msg->msg_flags |= MSG_TRUNC;
+ }
+
+ if (rds_cmsg_recv(inc, msg, rs)) {
+ ret = -EFAULT;
+ break;
+ }
+ rds_recvmsg_zcookie(rs, msg);
+
+ rds_stats_inc(s_recv_delivered);
+
+ if (msg->msg_name) {
+ if (ipv6_addr_v4mapped(&inc->i_saddr)) {
+ sin->sin_family = AF_INET;
+ sin->sin_port = inc->i_hdr.h_sport;
+ sin->sin_addr.s_addr =
+ inc->i_saddr.s6_addr32[3];
+ memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
+ msg->msg_namelen = sizeof(*sin);
+ } else {
+ sin6->sin6_family = AF_INET6;
+ sin6->sin6_port = inc->i_hdr.h_sport;
+ sin6->sin6_addr = inc->i_saddr;
+ sin6->sin6_flowinfo = 0;
+ sin6->sin6_scope_id = rs->rs_bound_scope_id;
+ msg->msg_namelen = sizeof(*sin6);
+ }
+ }
+ break;
+ }
+
+ if (inc)
+ rds_inc_put(inc);
+
+out:
+ return ret;
+}
+
+/*
+ * The socket is being shut down and we're asked to drop messages that were
+ * queued for recvmsg. The caller has unbound the socket so the receive path
+ * won't queue any more incoming fragments or messages on the socket.
+ */
+void rds_clear_recv_queue(struct rds_sock *rs)
+{
+ struct sock *sk = rds_rs_to_sk(rs);
+ struct rds_incoming *inc, *tmp;
+ unsigned long flags;
+
+ write_lock_irqsave(&rs->rs_recv_lock, flags);
+ list_for_each_entry_safe(inc, tmp, &rs->rs_recv_queue, i_item) {
+ rds_recv_rcvbuf_delta(rs, sk, inc->i_conn->c_lcong,
+ -be32_to_cpu(inc->i_hdr.h_len),
+ inc->i_hdr.h_dport);
+ list_del_init(&inc->i_item);
+ rds_inc_put(inc);
+ }
+ write_unlock_irqrestore(&rs->rs_recv_lock, flags);
+}
+
+/*
+ * inc->i_saddr isn't used here because it is only set in the receive
+ * path.
+ */
+void rds_inc_info_copy(struct rds_incoming *inc,
+ struct rds_info_iterator *iter,
+ __be32 saddr, __be32 daddr, int flip)
+{
+ struct rds_info_message minfo;
+
+ minfo.seq = be64_to_cpu(inc->i_hdr.h_sequence);
+ minfo.len = be32_to_cpu(inc->i_hdr.h_len);
+ minfo.tos = inc->i_conn->c_tos;
+
+ if (flip) {
+ minfo.laddr = daddr;
+ minfo.faddr = saddr;
+ minfo.lport = inc->i_hdr.h_dport;
+ minfo.fport = inc->i_hdr.h_sport;
+ } else {
+ minfo.laddr = saddr;
+ minfo.faddr = daddr;
+ minfo.lport = inc->i_hdr.h_sport;
+ minfo.fport = inc->i_hdr.h_dport;
+ }
+
+ minfo.flags = 0;
+
+ rds_info_copy(iter, &minfo, sizeof(minfo));
+}
+
+#if IS_ENABLED(CONFIG_IPV6)
+void rds6_inc_info_copy(struct rds_incoming *inc,
+ struct rds_info_iterator *iter,
+ struct in6_addr *saddr, struct in6_addr *daddr,
+ int flip)
+{
+ struct rds6_info_message minfo6;
+
+ minfo6.seq = be64_to_cpu(inc->i_hdr.h_sequence);
+ minfo6.len = be32_to_cpu(inc->i_hdr.h_len);
+ minfo6.tos = inc->i_conn->c_tos;
+
+ if (flip) {
+ minfo6.laddr = *daddr;
+ minfo6.faddr = *saddr;
+ minfo6.lport = inc->i_hdr.h_dport;
+ minfo6.fport = inc->i_hdr.h_sport;
+ } else {
+ minfo6.laddr = *saddr;
+ minfo6.faddr = *daddr;
+ minfo6.lport = inc->i_hdr.h_sport;
+ minfo6.fport = inc->i_hdr.h_dport;
+ }
+
+ minfo6.flags = 0;
+
+ rds_info_copy(iter, &minfo6, sizeof(minfo6));
+}
+#endif